syringe extruder for umo+

[Migo 1]

Hello, anyone have any experience with paste extruders ?

[SandervG 1,329]

What would you like to know? Do you know Discov3ry ?

[Migo 1]

i need a simple design to make for my umo+ .i have seen a lot .but all are mounted to the original extruder .

my umo+ has e3d hot end not like the original one 

so i need a bowden  design to fit on it 

i need to know how does it work ?

are there any modification that has to be made ?

[SandervG 1,329]

Would any of these files help? https://www.youmagine.com/designs/ultimaker-syringe-extruder-ii

[Migo 1]

yes ,it is .but i wonder how can the feeding mechanism can be done here?

[SandervG 1,329]

It should be mentioned in the files there. Basically you have to reverse the feeding (you can do this in the gcode by replacing all E values by -E, reverse some wires on your stepper motor or mount it the other way around), so the filament will pull instead of push. The pulling motion will pull down the top of the syringe, like how you would squeeze the contents out of it if you would do it manually.

Something like retraction is not possible. 

[geert_2 427]

In biomedical sciences people often use peristaltic pumps to transport liquids and thin pastes (=with a consistency similar to sirup, honey, yoghurt). For example to inject dead bodies with formol or other preservatives. But this will not work for thick pastes like choco, butter, thick glue, thick silicone. It all depends on the materials you want to extrude, and on the way they are delivered to you. If in bulk or in plastic bags like blood and water in hospitals then it should work. If in standard industrial silicone or glue syringes it will be very difficult.

 

If you are willing to do a bit of development, I think such a peristaltic pump concept might work for 3D-printing too. Connect the feeder motor to the shaft of the peristaltic pump (maybe via a reduction gear for more power), adjust e-steps, and instead of a bowden tube, use a silicone tube with a nozzle. In an UMO or UM2 you might be able to use the build-in provisions for the never unused second feeder and nozzle? At least, if the electronics board can handle a second feeder motor (I don't know which UM-models do have driver chips for a second feeder)?

 

Google "peristaltic pumps" > images. Maybe you could get some inspiration from these areas?